Re: [PATCH-tip v3 02/14] locking/rwsem: Make owner available even if !CONFIG_RWSEM_SPIN_ON_OWNER

[Peter Zijlstra]

On Wed, Apr 10, 2019 at 02:42:19PM -0400, Waiman Long wrote:
> The owner field in the rw_semaphore structure is used primarily for
> optimistic spinning. However, identifying the rwsem owner can also be
> helpful in debugging as well as tracing locking related issues when
> analyzing crash dump. The owner field may also store state information
> that can be important to the operation of the rwsem.
> 
> So the owner field is now made a permanent member of the rw_semaphore
> structure irrespective of CONFIG_RWSEM_SPIN_ON_OWNER.

sem->owner is still initialized under CONFIG_RWSEM_SPIN_ON_OWNER.